Alloy Basics: Precipitation Hardening Stainless Steel
An IPC Foundry Group team member preparing to pour a stainless steel part.
In this blog, we’ll explore the basics of Precipitation Hardening Stainless Steel (aka PH Stainless Steel), including its makeup, common uses, pros & cons, commonly poured alloys, and more.
About PH Hardening Stainless
Precipitation-hardening Stainless Steel (PH Stainless) is a special designation of alloys that marry the pros of both austenitic and martensitic stainless steels. Like other types of stainless steel, PH stainless contains iron, chromium, and nickel - but it also includes an assortment of additives such as copper, molybdenum, niobium, titanium, and aluminum that give it unique properties. At IPC, we frequently pour 15-5, 17-4, and 25-5 grades of PH hardening stainless.
When cast, PH Stainless steels are super strong, with tensile strength up to 1700 MPa, yield strengths of over 1400 MPa, and exceptional hardness. They also maintain corrosion resistance similar to other popular stainless options like 304.
This combination of strength, corrosion resistance, and rocksteady reliability make PH Stainless a popular choice in dozens of industries including automotive, pressure vessels, oil and gas, aerospace, military, power generation, and many more.
Pros & Cons of PH Hardening Stainless Steel
Pros
PH Stainless steels are tough! The various additives found in designations such as 17-4 or 15-5 allow it to be 3-4 times stronger than some other types of stainless. PH Stainless also has good retained ductility allowing it to withstand cracking, chipping, and other breakage.
Like all types of stainless steel, PH Stainless steels are corrosion resistant. The special additives and heat-treating process allow Precipitation-Hardening Stainless Steel variants to compete with the corrosion resistance of the super popular 304 Stainless steel.
Before heat treatment, PH Stainless designations like 17-4 are easily machinable, allowing companies to create high-performance components with complex geometry.
Overall, Precipitation-Hardening Stainless Steels are a super strong, resilient material that can take a beating and continually perform in exceptionally tough environments such as engines, oil and gas pressure valves, nuclear power generation, military applications, and beyond.
Cons
Perhaps the biggest drawback of casting PH Hardening Stainless Steels is the cost. Upfront material costs aside, post-casting heat treatment is frequently necessary and can further increase costs compared to lower alloyed steel. However, when usage applications require the strength and resistance that PH Stainless offers, these costs can quickly diminish compared to components made of a less hardy material. In short, if your demands require a material as tough and resilient as Precipitation Hardening Stainless, you'll be in good shape with an alloy in this family.
Precipitation Hardening Stainless Steels are commonly used in pressurized valve components due to their strength and corrosion resistance.
Applications of PH Stainless Steel Castings
PH Hardening Stainless Steel castings are used in dozens of industries. Here are just a few examples.
Oil, Gas, and Petrochemical: Gates, pressure vessels, pumps, valves, bearings, and more.
Aircraft & Aerospace: Fuel tank components, turbine components, landing gear covers, bolts, engine components, and more.
Automotive: Widespread usage in engine components
Marine Industry: Engine components, boilers, condensers, pressure vessels, and more.
Paper Processing: PH Hardening stainless is commonly used in paper milling and processing components.
Cast Your Precipitation Hardening
Stainless Steel Parts with IPC
The IPC Foundry Group has over 45 years of investment casting experience and can help you with all your casting needs, from engineering and development to finishing work and shipping.
If you’re interested in PH Hardening Stainless Steels, we frequently pour 15-5, 17-4, and 25-5 at our Utah and Texas facilities. Contact our expert team today to discuss your next project and quickly get a detailed, customized quote!
DisclaimerThis blog is meant to provide a quick look at PH Hardening Stainless Steel and is not a definitive guide or custom-tailored advice piece. For accurate, nuanced information for your particular project needs, we recommend continual research as well as contacting our team of experts to discuss your project.
